WorldCLASS:: Capacity Planner

"At Last - A Breakthrough In Mid-Range Planning"

Finite capacity planning has long been regarded as the 'black art' of manufacturing management. Its function seems simple enough: to match the demand to the available production facilities over a certain timescale. However, the practice of utilising capacity as effectively as possible still remains an elusive goal for many companies.

Effective capacity planning requires three stages. Firstly, assuming infinite capacity, a plan is created from the demand forecast and current sales orders, taking into account manufacturing methods and delivery dates. Secondly, each resource type is analysed for capacity overloads. Then finally the plan is modified to smooth these overloads, optionally utilising any slack and producing revised plan dates, which become the available to promise (A-T-P) dates.

While many companies experience some difficulty creating their plan and identifying the overloads, even fewer have mastered the ability to re-plan effectively. This is mainly due to the complexity of modern manufacturing, where a minor change to one element of the plan can have major, sometimes unforseen, effects in other areas.

The WorldCLASS CAPACITY PLANNER provides a breakthrough in this challenging area of production control. For the first time, company planners are able to create realistic capacity plans, smooth capacity overloads and produce revised plan dates, automatically and without compromising manufacturing methods.

The Problem In Perspective

Traditionally, finite capacity planning has been performed manually or by using a spreadsheet. With the growing complexity of modern manufacturing, such methods have proved inadequate. The problem is that planning within one work centre (machine, machine group, product line and alternative line(s) etc.) is invariably affected by previous and subsequent operations.

Although MRP and ERP software tools have been partially effective in addressing the problem, they only plan to an infinite capacity and then identify capacity overloads. They do not provide a means of 'smoothing the load'.

This leads to:

  • Unrealistic loadings which lead to missed due dates.
  • Unreliable A-T-P dates.
  • Longer lead times and production cycle than is necessary.
  • Difficulty in estimating available capacity for rush orders e.g. short notice promotions.
  • Extra cost of overtime of shift work.
  • Stock control with shelf life and storage space constraints.
  • Raw material availability and transport / logistics of deliveries.
  • Bottlenecks of machines and people.
  • Extra work for production planners and shift teams.

  • The WorldCLASS CAPACITY PLANNER addresses these problems by taking capacity planning beyond simple static analysis and into dynamic control where planners can act upon all pertinent information to create best initial, and subsequently as necessary, revised plan dates.

    "A powerful decision support tool" the WorldCLASS CAPACITY PLANNER liberates managers from the rigour of systematic, step-by-step, day-by-day planning."

    Smoothing The Peaks And Troughs

    The WorldCLASS CAPACITY PLANNER smoothes the peaks and troughs of production imbalance by bringing forward or pushing back batches.

    The system first tries to move the highest priority order or batch in the overload 'time bucket'. The priority can be customer or product based. Alternatively it can be a variable calculated from, for example, the closeness to due date or lateness.

    This order/batch is then moved forward, on the same resource or resource type, to the next slot of available capacity. The previous operation is then identified from the manufacturing data and also moved forward at least the same amount of time to the next available capacity slot on the resource. In this way, the timing relationship between operations is maintained.

    This process is continued until all previous operations are successfully re-planned or one is moved forward into the commitment horizon where no changes are allowed. In the latter case, the original plan dates are reinstated and the next highest priority order/batch is brought forward instead.

    If none of the overload can be moved forward, then the lowest priority order/batch is selected and moved out. This may result in a revised due date, which is why the lowest priority is selected.

    If the planned resource is flexible, such as labour, then overtime or extra shifts can be planned and the effect analysed using the 'what-if' tools within the WorldCLASS CAPACITY PLANNER.

    "With the WorldCLASS CAPACITY PLANNER, management's decision support is improved, customer service is enhanced and 'guestimating' is all but eliminated".


    The WorldCLASS CAPACITY PLANNER has access to a manufacturing database that includes information on forecast demand, orders required delivery dates resource availability, planned shifts and manufacturing methods. Combining this data with an in-built algorithm, the system initiates a three-stage planning process.

    In the first stage, demand is planned either forward from a launch date or backwards from a due date, assuming infinite resources. In the second stage, the resource profile is compared against the planned availability for each resource and the overloads identified. In the third stage, the plan is modified to smooth any overloads.


    The WorldCLASS CAPACITY PLANNER's smoothing algorithm works by moving forward the highest priority order or batch in the overload 'time bucket' while taking into account the previous operations.

    If any revised plan dates fall within the commitment horizon - where no changes are allowed - the next highest priority order/batch is selected instead. If none of the overload can be moved forward, then the lowest priority is moved out.

    The Result

    The result is a set of plan dates - including revised launch dates or delivery dates - which can be fed back to a plant level system such as ERP (or MRP) to check for material availability.

    The WorldCLASS CAPACITY PLANNER can also be used in 'what-if' mode to predict the consequence of factors such as rush orders, seasonal peak workload, extra shifts and planned maintenance.


    The WorldCLASS CAPACITY PLANNER can be used on its own or integrated with existing MRP, stock control or financial systems. It may also be employed as a pre-stage to the WorldCLASS SCHEDULER and WorldCLASS SFDC systems.

    Additional detailed functionality

    The WorldCLASS::Capacity Planner uniquely meets the following market needs of manufacturers operating in the real world:

    (i) the ability to handle customers reservations.
    Customers place non-specific orders to reserve blocks of capacity some days or weeks ahead. A capacity planning system needs to be able to manipulate this data in an easy to use manner, both in reserving capacity as the non-specific orders are loaded, and in consuming capacity as the orders become specific or in freeing up "real" capacity should only part of the reservation be firmed up.

    (ii) the ability to handle overdues, by an overdue catch up method.
    Most systems assume that once the (scheduling) system is implemented, overdues will be a thing of the past. This is because the whole idea of implementing a scheduler is to achieve 100% on time delivery. Providing a facility to cope with overdues would be admitting failure in advance. Right? No, this is wrong! It is in the nature of most businesses to have some jobs which will not run correctly first time (tooling) or fail test (quality) or only get part made (shortages.) As much as ignoring the problem is wrong, it is equally wrong to assume these items will be remade on day 0, or part of day 1. Apart from the fact that overdues often consume 3-4 days work, it is impractical to make them all in advance of unmade new orders because it will push these current orders late. Overdues are self perpetuating in an environment where there are significant overdues and the plan each month is to make all of these in the current month (or worse - make these first.) A proportion of the current orders (equal to the overdues) is bound to be late as a consequence with this strategy if each month has been loaded to capacity. There has to be a better way! And there is. The planning system must handle a proportion of overdues to be made each day, e.g. allocate a band equal to 10% of overdues for "overdue catchup" with the ability to drag forward more overdues if production exceeds expectations and today's load is light....etc. If all goes according to plan, in 10 days time the overdues will be gone, at no expense to the on time delivery of current orders.

    (iii) the ability to handle set ups "broad brush" and in detail. Scheduling rightly requires the sequence of jobs to be detailed including the timing of "major" and "minor" set up changes In a capacity planner, days or weeks ahead, it would be a nonsense to require (for example our non-specific reservation) orders to be sequenced and set ups to be specified, because apart from the fact that the detail is often not known that far ahead, there is no possibily that a schedule set in stone that far ahead will ever come to fruition. Nevertheless since set ups take up a significant chunk of capacity these do have to be taken into account by the capacity planner at a broad brush level, and to be consumed or freed up at a detailed level as today's schedule and the net shifts work to list is system produced.

    (iv) other features include the ability to transfer jobs within machines at a machine centre by a "drag and drop" method, whereby the job when "manually" transferred by the Production Control Manager from machine x to another machine y (perhaps to free capacity for a product that can only run on machine x) will automatically transfer if sufficient capacity units are available, else will be dragged back to machine x if insufficient capacity is available.

    Many of these features are not available in any competitive products to-date. In addition, as a result of the various WorldCLASS::implementations, for example at McDougalls Foods, the WorldCLASS::Capacity Planner now contains functionality unique to those industries, so that in FMCG industry, plan (schedule) to the Dynamic Minimum Balance (days cover at item level), adhere to product specific weekly cycles, move overload on a pro-rata basis etc.... is now standard available functionality.

    Please contact the WorldCLASS Sales Office for further information, on:
    +44 1386 871904

    or e-mail us
    Stephen Foster